The role of staging CT scans in the treatment of prostate cancer: a retrospective audit.

A retrospective audit was performed to review the use of diagnostic and planning computed tomographic (CT) scans in the management of patients treated with radical radiotherapy for prostate cancer at Mount Vernon Hospital. All 97 patients had a planning CT scan. In addition, 85 also underwent a diagnostic scan for staging purposes. Fifty-one (60%) had both pelvic and abdominal imaging. Twenty abnormalities were detected in 19 patients. Although 13 of these were 'malignant' abnormalities considered to represent metastatic disease, only four altered the treatment intent. Overall, only 4% of patients were denied radical treatment on the basis of CT findings. Malignant intra-abdominal disease was not identified in the absence of metastatic disease in the pelvis. This study confirms that abdominal CT scans contribute very little useful prognostic information in men with prostate cancer, and are not necessary for routine staging prior to radiotherapy. We propose that a single CT scan of the pelvis in patients who are suitable for radical radiotherapy can provide adequate information for both staging and planning purposes, resulting in significant reductions in cost, radiation exposure and scanner time.